<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script !src="">

    var str = "Hello javaScript"
//    正则表达式
    var patt = /java/i

    console.log(str.match(patt))
    console.log(patt.test(str))
    console.log(patt.exec(str))

</script>
</body>
</html>